Lift ladder

ABSTRACT

A lift ladder has a support frame with two support bars each having a U-shaped portion and a vertical support portion. A transverse bar is disposed between the two supporting bars at the vertical support portion. The transverse bar has a catch member. A guide member is provided at an end of the vertical support portion of each of the support bars. The guide member is formed with a cutout. A ladder body to be supported by the support frame includes two vertical support members each to be slidably guided by a respective guide member. Rungs operatively engage with the catch member to fix the ladder in a position. A locking member is formed on each of the two vertical support members. The locking member is shaped to fit into the cutout of the guide member for minimizing movement of the ladder body with respect to the support frame.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention lies in the field of ladders, especially marine laddersused on swim floats, docks, seawalls, etc. The invention relates to alift ladder that can be extended and retracted between a maximumextended position and a maximum retracted position and, thus, beadjusted to various heights. More specifically, the invention relates toa lift ladder that can be safely secured in any desired position.

Lift ladders for marine application exist in the prior art. Applicant'sU.S. Pat. No. 6,422,340 B1 (Grundler), for example, shows such a liftladder, which has a catch mechanism for supporting the rungs of theladder and a stop member for defining the maximum height of the liftladder.

However, the lift ladder as shown in U.S. Pat. No. 6,422,340 has aproblem of swinging when the ladder is extended to the maximum extent,which may be caused by the wind or a wake created by a boat, forexample. The swaying of the ladder can cause injury to a person swimmingtoward the ladder or to a person climbing the ladder. When mooring aboat, the swaying of the ladder can also cause damage to the boat.

Therefore, there is a need for an improved lift ladder that can be moresafely secured in the maximum extended position to prevent injuries topersons or damage to boats.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide an improved liftladder that can be more safely secured in the maximum extended position.

With the foregoing and other objects in view, there is provided, inaccordance with the invention, a lift ladder, comprising:

-   -   a support frame having two support bars, each of the support        bars having:        -   a U-shaped portion; and        -   a vertical support portion having an end;    -   a transverse bar disposed between the two support bars at the        vertical support portion, the transverse bar having a catch;    -   guide members provided at the end of the vertical support        portion of each of the support bars, at least one of the guide        members defining a cutout; and    -   a ladder body movably supported by the support frame, the ladder        body having:        -   two vertical support members each slidably guided by a            respective one of the guide members;        -   rungs each releasably engaged with the catch for setting a            vertical position of the ladder body with respect to the            support frame; and        -   a locking member formed on at least one of the two vertical            support members, the locking member shaped to fit into the            cutout for reducing movement of the ladder body with respect            to the support frame.

In accordance with another feature of the invention, each of the guidemembers defines a cutout; and a locking member is formed on each of thetwo vertical support members, the locking members each shaped to fitinto the cutout.

In accordance with a further feature of the invention, the lockingmember reduces lateral movement of the ladder body with respect to thesupport frame when disposed in the cutout.

In accordance with an added feature of the invention, the support framehas a longitudinal extent; and the locking member reduces movement ofthe ladder body in a direction orthogonal to the longitudinal extentwhen disposed in the cutout.

In accordance with an additional feature of the invention, the ladderbody has an end; and the locking member is disposed on the verticalsupport member from a second uppermost one of the rungs to the end ofthe ladder body.

In accordance with yet another feature of the invention, the lockingmember is disposed on the vertical support member substantially at thesecond uppermost rung.

In accordance with yet a further feature of the invention, the ladderbody has an end; and the locking members are disposed on a respectiveone of the vertical support members from a second uppermost one of therungs to the end of the ladder body.

In accordance with yet an added feature of the invention, the lockingmembers are disposed on a respective one of the vertical support memberssubstantially at a location of the second uppermost rung.

In accordance with yet an additional feature of the invention, the catchhas a L-shape; the rungs have a ceiling and two sides in an upside-downU-shape; and one of the sides operatively connects with the catch toreleasably fix the ladder body in a position.

In accordance with another feature of the invention, there is provided acable for connecting a respective one of the vertical support members ofthe ladder body to a respective one of the support bars.

With the foregoing and other objects in view, there is also provided, inaccordance with the invention, a lift ladder, comprising:

-   -   a ladder body having rungs and a locking member;    -   a support frame slidably supporting the ladder body and having:        -   a guide member for guiding the ladder body between a stowed            position and at least one extended position; and        -   a catch releasably engaging one of the rungs in at least one            of the stowed position and the at least one extended            position; and    -   the locking member operatively connecting the guide member and        locking the ladder body at the at least one extended position.

With the foregoing and other objects in view, there is also provided, inaccordance with the invention, a lift ladder, comprising:

-   -   a support frame having:        -   two substantially vertically oriented hand rails having a            lower portion; and        -   a transverse bar fixedly connecting the two hand rails to            one another, the transverse bar having a catch;    -   at least one guide member provided at the lower portion of at        least one of the hand rails, the at least one guide member        defining a cutout; and    -   a ladder body movably supported by the support frame, the ladder        body having:        -   rungs each releasably engaged with the catch for setting a            position of the ladder body with respect to the support            frame; and        -   a locking member formed on at least one of the two vertical            support members, the locking member shaped to fit into the            cutout for reducing movement of the ladder body.

Other features that are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a lift ladder, it is, nevertheless, not intended to be limited to thedetails shown because various modifications and structural changes maybe made therein without departing from the spirit of the invention andwithin the scope and range of equivalents of the claims.

Additional advantages of the invention will be set forth in part in thedescription which follows, and in part will be clear from thedescription, or may be learned by practice of the invention. Theadvantages of the invention will be realized and attained by theelements and combinations particularly pointed out in the appendedclaims. It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, perspective view of a lift ladder according tothe invention secured to a dock;

FIG. 2 is a perspective view of the lift ladder of FIG. 1 in a retractedposition;

FIG. 3 is a perspective view of the lift ladder of FIG. 1 in a maximumextended position;

FIG. 4 is fragmentary cross-sectional view along section line IV-IV inFIG. 3; and

FIG. 5 is fragmentary cross-sectional view along section line V-V inFIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention may be understood more readily by reference to thefollowing detailed description of preferred embodiments of theinvention.

Before the invention is disclosed and described, it is to be understoodthat the terminology used herein is for the purpose of describingparticular embodiments only and is not intended to be limiting. It mustbe noted that, as used in the specification and the appended claims, thesingular forms “a,” “an” and “the” include plural referents unless thecontext clearly dictates otherwise.

The invention will now be described in detail with reference to theaccompanying drawings.

Referring now to the figures of the drawings in detail and first,particularly to FIG. 1 thereof, there is shown a lift ladder 100according to the invention having a support frame 110 fixed to a dock200 and a ladder body 120 that can be slidably supported by the supportframe 110. The support frame 110 includes two support bars 111, eachhaving a U-shaped portion 112 and a vertical support portion 113, and atransverse bar 115 with a L-shaped catch member 116 disposed between thetwo vertical support portions 113 of the support bars 111. The U-shapedportions 112 of the support bars 111 are each fixed to the dock 200 by atie-down member 114 or by any other measures. A guide member 117 isprovided at an end 113′ of a respective vertical support portion 113 ofthe support bar 111 for guiding the ladder body 120 during the extensionand retraction movements. Each guide member 117 has a cutout 118 formedtherein. The ladder body 120 has two vertical support members 121 and aplurality of U-shaped rungs 122 adapted to engage with the L-shapedcatch member 116 to support the ladder body 120 with the support frame110. Each of the vertical support members 121 has at least one lockingmember 123 projecting outwardly therefrom. In a preferred embodiment, asingle locking member 123 is formed between the uppermost rung 122 andthe second uppermost rung 122 of the ladder body 120. The locking member123 is shaped to fit into the cutout 118 of the guide member 117.However, each vertical support members 121 may be provided with morethan one locking members 123. For example, another locking member 123may be provided on the vertical support members 121 at the lowermostrung 122.

FIG. 2 shows the lift ladder 100 in a retracted position. Cables 300 areprovided to connect the ladder body 120 to the U-shaped portion 112 ofthe support bar 111. The cables 300 can facilitate the extending andretracting movements of the ladder body 120 and more particularly,prevent the ladder body 120 from being lost in the water if it isdropped or knocked loose. As shown in FIG. 2, the U-shaped rung 122second from the bottom of the ladder body 120 is engaged with theL-shaped catch member 116 on the transverse bar 115 of the support frame110.

In comparison to FIG. 2, FIG. 3 shows the lift ladder 100 in a maximumextended position, in which the uppermost rung 122 of the ladder body120 is engaged with the catch member 116 on the transverse bar 115 ofthe support frame 110. Each locking member 123 on the ladder body 120fits into the cutout 118 of the respective guide member 117 to providethe ladder body 120 with additional stability.

FIG. 4 even more clearly shows the connection between the catch member116 and the rung 122. FIG. 4 illustrates how the upside-down U-shapedrung 122 of the ladder body 120 is engaged with the L-shaped catchmember 116 formed on the transverse bar 115 of the support member 110.In this view, it can be seen that the transverse bar/support member115/116 connection is a pivot, about which the ladder body 120 canrotate. It is this pivoting motion that the cutout/locking member118/123 prevents.

FIG. 5 clearly shows how the locking member 123 fits into the cutout 118of the guide member 117. Specifically, the cutout 118 has a diameter118′ that is slightly greater than a diameter 123′ of the locking member123. Because of this relatively tight fit, the two contact points(115/116 and 118/123) are stable and do not present a pivot for movementof the lowermost portion of the ladder body 120 when it is subjected tothe moving force of water, or any other force. When a locking member 123is provided on the vertical support members 121 at the lowermost rung122, the two contact points (115/116 and 118/123) can also prevent theuppermost portion of the ladder body 120 from swiveling at a stowedposition due to the wind.

As can be seen from FIG. 5, the distance between the two verticalsupport members 121 of the ladder body 120 is slightly smaller than thedistance between the two vertical support portions 113 of the supportbars 111 of the support frame 110 to accommodate the ladder body 120within the guide members 117 on the vertical support portions 113.

It is apparent from the above description that the lift ladder 100according to the invention has an advantage over the prior art—theladder body 120 can be secured with additional stability to prevent theladder body 120 from swaying, thus, preventing injury to a person ordamage to a boat.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only.

1. A lift ladder, comprising: a support frame having two support bars,each of said support bars having: a U-shaped portion; and a verticalsupport portion having an end; a transverse bar disposed between saidtwo support bars at said vertical support portion, said transverse barhaving a catch; guide members provided at said end of said verticalsupport portion of each of said support bars, at least one of said guidemembers defining a cutout; and a ladder body movably supported by saidsupport frame, said ladder body having: two vertical support memberseach slidably guided by a respective one of said guide members; rungseach releasably engaged with said catch for setting a vertical positionof said ladder body with respect to said support frame; and a lockingmember formed on at least one of said two vertical support members, saidlocking member shaped to fit into said cutout for reducing movement ofsaid ladder body with respect to said support frame.
 2. The lift ladderaccording to claim 1, wherein: each of said guide members define acutout; and a locking member is formed on each of said two verticalsupport members, said locking members each shaped to fit into saidcutout.
 3. The lift ladder according to claim 1, wherein said lockingmember reduces lateral movement of said ladder body with respect to saidsupport frame when disposed in said cutout.
 4. The lift ladder accordingto claim 1, wherein: said support frame has a longitudinal extent; andsaid locking member reduces movement of said ladder body in a directionorthogonal to said longitudinal extent when disposed in said cutout. 5.The lift ladder according to claim 1, wherein: said ladder body has anend; and said locking member is disposed on said vertical support memberfrom a second uppermost one of said rungs to said end of said ladderbody.
 6. The lift ladder according to claim 5, wherein said lockingmember is disposed on said vertical support member substantially at saidsecond uppermost rung.
 7. The lift ladder according to claim 2, wherein:said ladder body has an end; and said locking members are disposed on arespective one of said vertical support members from a second uppermostone of said rungs to said end of said ladder body.
 8. The lift ladderaccording to claim 7, wherein said locking members are disposed on arespective one of said vertical support members substantially at alocation of said second uppermost rung.
 9. The lift ladder according toclaim 1, wherein: said catch has a L-shape; said rungs have a ceilingand two sides in an upside-down U-shape; and one of said sidesoperatively connects with said catch to releasably fix said ladder bodyin a position.
 10. The lift ladder according to claim 1, furthercomprising a cable for connecting a respective one of said verticalsupport members of said ladder body to a respective one of said supportbars.
 11. A lift ladder, comprising: a ladder body having rungs and alocking member; a support frame slidably supporting said ladder body andhaving: a guide member for guiding said ladder body between a stowedposition and at least one extended position; and a catch releasablyengaging one of said rungs in at least one of said stowed position andsaid at least one extended position; and said locking member operativelyconnecting said guide member and locking said ladder body said at leastone extended position.
 12. The lift ladder according to claim 11,wherein said support frame has a transverse bar and said catch is formedon said transverse bar.
 13. The lift ladder according to claim 12,wherein: said guide member defines a cutout; and said locking memberfits into said cutout for minimizing movement of said ladder body withrespect to said support frame.
 14. The lift ladder according to claim11, wherein: said guide member is two guide members each defining acutout; and said locking member is two locking members each shaped tofit into said cutout.
 15. The lift ladder according to claim 11, whereinsaid locking member reduces lateral movement of said ladder body withrespect to said support frame when disposed in said cutout.
 16. The liftladder according to claim 11, wherein: said support frame has alongitudinal extent; and said locking member reduces movement of saidladder body in a direction orthogonal to said longitudinal extent whendisposed in said cutout.
 17. The lift ladder according to claim 11,wherein: said ladder body has an end; and said locking member isdisposed on said ladder body from a second uppermost one of said rungsto said end of said ladder body.
 18. The lift ladder according to claim11, wherein: said catch is L-shaped; said rungs have a ceiling and twosides in an upside-down U-shape; and one of said sides operativelyconnects with said catch to releasably fix said ladder body in at leastone of said stowed position and said at least one extended position. 19.A lift ladder, comprising: a support frame having: two substantiallyvertically oriented hand rails having a lower portion; and a transversebar fixedly connecting said two hand rails to one another, saidtransverse bar having a catch; at least one guide member provided atsaid lower portion of at least one of said hand rails, said at least oneguide member defining a cutout; and a ladder body movably supported bysaid support frame, said ladder body having: rungs each releasablyengaged with said catch for setting a position of said ladder body withrespect to said support frame; and a locking member formed on at leastone said two vertical support members, said locking member shaped to fitinto said cutout for reducing movement of said ladder body.
 20. The liftladder according to claim 19, wherein: said at least one guide member istwo guide member each defining a cutout; a locking member is two lockingmembers formed on each of said two hand rails; and said locking membersare each shaped to fit into said cutout.
 21. The lift ladder accordingto claim 19, wherein said locking member reduces lateral movement ofsaid ladder body with respect to said support frame when disposed insaid cutout.
 22. The lift ladder according to claim 19, wherein: saidsupport frame has a longitudinal extent; and said locking member reducesmovement of said ladder body in a direction orthogonal to saidlongitudinal extent when disposed in said cutout.
 23. The lift ladderaccording to claim 19, wherein: said ladder body has an end; and saidlocking member is disposed on said ladder body from a second uppermostone of said rungs to said end of said ladder body.
 24. The lift ladderaccording to claim 23, wherein said locking member is disposed on saidladder body substantially at said second uppermost rung.
 25. The liftladder according to claim 19, wherein: said catch has a L-shape; saidrungs have a ceiling and two sides in an upside-down U-shape; and one ofsaid sides operatively connects with said catch to releasably fix saidladder body in a position.
 26. The lift ladder according to claim 19,further comprising a cable for connecting a respective one of saidvertical support members of said ladder body to a respective one of saidsupport bars.